Optimization of Dialysis Fistula Maturation via Vascular Ultrasound Elasticity and Shear Rate Imaging R21: NIH PI: William Weitzel, MD Co-I: Albert Shih, PHD, Grant Kruger, Matthew Leavitt, Peter Henke Abstract Vascular access is crucial to the treatments necessary for hemodialysis patients. Due to their reliability, longevity, and lower complication rates, autogenous arteriovenous fistulas - surgically created connections between arteries and veins - have become increasingly prominent over other forms of vascular access. However, the uncertainty associated with fistula maturation has caused undue cost, risk, and stress to patients already undergoing significant medical procedures. Currently no system exists to directly and noninvasively measure the underlying causes of vascular remodeling during fistula maturation. We propose to build an ultrasound software toolbox - referred to as the vascular ultrasound elastography and shear rate (VUESR) imaging - that has unprecedented temporal and spatial resolution to identify vessel wall edges and measure vessel size, elastic properties, and blood-wall shear rate during the cardiac cycles. After validating thi tool both in vitro (through phantom studies on simple and realistic fistula geometries) and in vivo (a pilot study conducted on a small sample of hemodialysis patients pre- and post-fistula creation), we plan to release the software necessary for this technique available in the public domain as an open platform tool for researchers. This software tool will be useful for pre-operative planning and post-operative assessment to guide decisions for angioplasty and surgical revision. Given the ubiquity and noninvasive nature of ultrasound imaging and the broad open access with which we plan to release this tool, this proposal can radically accelerate safe and effective ultrasound diagnostic methods for fistula optimization.